摘要:
A radio frequency amplification stage comprising: an amplifier for receiving an input signal to be amplified and a power supply voltage; and a power supply voltage stage for supplying said power supply voltage, comprising: means for providing a reference signal representing the envelope of the input signal; means for selecting one of a plurality of supply voltage levels in dependence on the reference signal; and means for generating an adjusted selected power supply voltage, comprising an ac amplifier for amplifying a difference between the reference signal and one of the selected supply voltage level or the adjusted selected supply voltage level, and a summer for summing the amplified difference with the selected supply voltage to thereby generate the adjusted supply voltage.
摘要:
An amplifier circuit has a voltage input terminal, for receiving Vin, and a voltage output terminal, for outputting Vout. A feedback circuit controls Vout to match Vin. A differential input stage receives Vin and Vout and generates a first output signal. An output stage comprises a pull down circuit for Vout. A main MOSFET is controlled by the first output signal to pull down Vout to match Vin when Vout is above a threshold voltage Vtrans. An auxiliary MOSFET, in parallel with the main MOSFET, is controlled by the first output signal to pull down Vout to match Vin when Vout is below Vtrans. The main MOSFET is turned substantially off when Vout is below Vtrans. A headroom generator coupled between the Vout terminal and a drain of the auxiliary MOSFET allows the auxiliary MOSFET to operate in its active region and pull Vout to ground.
摘要:
An integrated circuit includes a radio frequency (RF) amplifier having a trifilar transformer coupled to a gain device in two negative feedback paths. The trifilar transformer includes a first winding, a second winding and a third winding, a first dielectric core is disposed between the first winding and the second winding, and a second dielectric core is disposed between the second winding and the third winding. A first winding ratio between the first winding and the second winding combined with a second winding ratio between the second winding and the third winding affects a total gain of the RF amplifier. In a specific embodiment, the gain device is a transistor, the first winding is coupled to a base of the transistor, the second winding is coupled to a collector of the transistor, and the third winding is coupled to an emitter of the transistor.
摘要:
A radio frequency amplification stage comprising: an amplifier for receiving an input signal to be amplified and a power supply voltage; and a power supply voltage stage for supplying said power supply voltage, comprising: means for providing a reference signal representing the envelope of the input signal; means for selecting one of a plurality of supply voltage levels in dependence on the reference signal; and means for generating an adjusted selected power supply voltage, comprising an ac amplifier for amplifying a difference between the reference signal and one of the selected supply voltage level or the adjusted selected supply voltage level, and a summer for summing the amplified difference with the selected supply voltage to thereby generate the adjusted supply voltage.
摘要:
A reference potential converter circuit comprises: a first resistor (resistance value R1) serving as a feedback resistor for an operational amplifier; a second resistor (resistance value R2) connected to the first resistor and a reference voltage; and a third resistor (reference value R3) and a fourth resistor (reference value R4) connected between a power supply and ground. A difference voltage between Vout and Vref is divided by an R1/R2 ratio and applied to an inverting input terminal of the operational amplifier. A power supply voltage is divided by an R3/R4 ratio and applied to a non-inverting input terminal of the operational amplifier. The R1/R2 ratio and the R3/R4 ratio are equal.
摘要:
A radio frequency amplification stage comprising: an amplifier for receiving an input signal to be amplified and a power supply voltage; and a power supply voltage stage for supplying said power supply voltage, comprising: means for providing a reference signal representing the envelope of the input signal; means for selecting one of a plurality of supply voltage levels in dependence on the reference signal; and means for generating an adjusted selected power supply voltage, comprising an ac amplifier for amplifying a difference between the reference signal and one of the selected supply voltage level or the adjusted selected supply voltage level, and a summer for summing the amplified difference with the selected supply voltage to thereby generate the adjusted supply voltage.
摘要:
A control signal generation circuit includes a voltage detection unit which detects a level of an external voltage and generates first and second detection signals and a control signal control unit which delays a sense amplifier enable signal in response to the first and second detection signals and generates first through third control signals. The enable period of the first and second control signals are controlled based on the levels of the first and second detection signals.
摘要:
A radio frequency amplification stage comprising: an amplifier for receiving an input signal to be amplified and a power supply voltage; and a power supply voltage stage for supplying said power supply voltage, comprising: means for providing a reference signal representing the envelope of the input signal; means for selecting one of a plurality of supply voltage levels in dependence on the reference signal; and means for generating an adjusted selected power supply voltage, comprising an ac amplifier for amplifying a difference between the reference signal and one of the selected supply voltage level or the adjusted selected supply voltage level, and a summer for summing the amplified difference with the selected supply voltage to thereby generate the adjusted supply voltage.
摘要:
An AV amplifier contains an input unit to input digital data and an operation unit that receives a reproduction instruction. A switching unit switches whether to output the digital data input to a server interface unit or DSP in response to the reproduction instruction. The DSP processes the digital data output to obtain and output a two-channel signal, which the server interface unit transmits by the switching unit to a server and receives an audio signal from the server. An audio reproduction unit reproduces the server interface unit received audio signal and an audio signal output by the DSP. An output unit outputs the reproduced audio signal to each speaker and a control unit controls the switching unit and the server interface unit in response to the reproduction instruction from the user. The control unit controls the switching unit, when two-channel audio reproduction is instructed from the user.
摘要:
The present disclosure relates to a transmitter for transmitting a transmit signal comprising a first signal portion and a second signal portion. The transmitter comprises a power amplifier configured to amplify the transmit signal. The power amplifier is prone to undesired gain variations during the first and the second signal portion. The transmitter further comprises a transmit feedback receiver coupled to an output of the power amplifier and configured to feed back the transmit signal to generate a fed back first signal portion and a fed back second signal portion. Processing circuitry is configured to determine a first gain relation between the fed back first signal portion and the first signal portion and to determine at least one second gain relation between the fed back second signal portion and the second signal portion. Power adjustment circuitry is configured to adjust a transmit power of the transmit signal according to a variation between the first gain relation and the second gain relation.